LOANS RECEIVABLE AND INVESTMENTS (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for-sale securities, unrealized gain (loss)	$ 8,133,000		$ 6,784,000
Secured loans, unsecured loans, and other available-for-sale securities, carrying amount	886,430,000		927,664,000
Secured loans, unsecured loans, and other available-for-sale securities, amortized cost	878,297,000		920,880,000
Secured loans, unsecured loans, and other available-for-sale securities, fair value	923,251,000		937,114,000
Purchase of marketable securities	0	25,000,000
Investment in loans receivable and other	39,573,000	1,192,000
Total proceeds from sale or maturity of marketable securities			22,300,000
Recognized gain on sale of marketable securities			600,000
Proceeds from sale of loans	86,200,000		55,900,000
Gain on the repayment of loans receivable	1,500,000		5,200,000
Secured notes and loans receivable, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for-sale securities, unrealized gain (loss)	1,783,000		1,738,000
Secured loans, unsecured loans, and other available-for-sale securities, carrying amount	773,773,000		829,756,000
Secured loans, unsecured loans, and other available-for-sale securities, amortized cost	771,990,000		828,018,000
Secured loans, unsecured loans, and other available-for-sale securities, fair value	808,716,000		837,904,000
Other assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for-sale securities, unrealized gain (loss)	6,350,000		5,046,000
Secured loans, unsecured loans, and other available-for-sale securities, carrying amount	112,657,000		97,908,000
Secured loans, unsecured loans, and other available-for-sale securities, amortized cost	106,307,000		92,862,000
Secured loans, unsecured loans, and other available-for-sale securities, fair value	114,535,000		99,210,000
Government-sponsored pooled loan investments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for-sale securities, amortized cost basis	61,539,000		61,377,000
Available-for-sale securities, fair value and carrying amount	63,322,000		63,115,000
Available-for-sale securities, unrealized gain (loss)	1,783,000		1,738,000
Investment in loans receivable and other			38,700,000
Marketable securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for-sale securities, amortized cost basis	71,000,000		71,000,000
Available-for-sale securities, fair value and carrying amount	77,350,000		76,046,000
Available-for-sale securities, unrealized gain (loss)	6,350,000		5,046,000
Senior unsecured corporate bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of marketable securities			71,000,000
Marketable equity securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of marketable securities			21,700,000
Secured mortgage loans and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Secured loan receivable, carrying amount and amortized cost	710,451,000		766,641,000
Mortgage loans, fair value	745,394,000		774,789,000
Number of loans sold	1		3
Secured mortgage loans and other | Mezzanine Loan Investment Due 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment in loans receivable and other			425,000,000
Secured loan receivable, interest rate			8.10%
Unsecured loans receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Secured loan receivable, carrying amount and amortized cost	35,307,000		21,862,000
Mortgage loans, fair value	$ 37,185,000		$ 23,164,000
Number of loans sold	1		2